Boeing Defense, in partnership with Saab Dynamics, on 26 September conducted a long-range test firing of the Ground-Launched Small Diameter Bomb (GLSDB) from the Andøya Space Center in Andenes, Norway.
The Andøya shot marks the third official firing event of GLSDB; earlier shots were conducted at the Vidsel Test Range in Sweden in March 2015 and – in co-operation with the US Army Aviation & Missile Research, Development and Engineering Center (AMRDEC) – at the US Air Force Eglin Gulf Test and Training Range in Florida in 2017.
For the September test, GLSDB was launched in “challenging conditions” from a customised, fully autonomous ISO container, out to a range of 130 km at a pre-determined target area in the sea. “The Andøya Test Center is one of the very few, if not the only, firing ranges in Europe where we can fire at ranges out to 150 km,” Svein Daae, Saab director of marketing, GLSDB, explained to Jane’s .
“The target area was out in the open sea, where the depth is about 2,000–3,000 m, which makes it very difficult to anchor a target. Therefore, we decided to aim at a point in the sea, crosshair-designated by an overhead drone.”
“We’d shortened the shot down to 130 km to ensure that we had very accurate telemetry data. Drone imagery from the shot showed that we’d hit the crosshair precisely, with a very high impact angle; telemetry data determined that, despite the conditions, including strong headwinds, we could have hit a target well beyond 150 km,” Daae added.
In addition, the test was able to determine the effects of launching GLSDBs from a container, in terms of damage, test pressure, and incidental heat surplus. A typical containerised autonomous GLSDB configuration comprises two co-mounted launch pods – identical to those in the M270 High Mobility Artillery Rocket System (HIMARS) – each with six GLSDB rounds.
The GLSDB/ISO container concept was introduced earlier this year during Bold Quest 19.1 – a multinational joint fires interoperability demonstration and assessment event, held in April–May in Finland, and sponsored and facilitated by the US Joint Staff. “The Norwegian Army had a mock-up in the container and ‘simulated’ long-range fire support from the container’s position. They tested it in the strategic scenario during the exercise, to see how such capacity would influence the scenario, and possibly learn how to use it in the command chain,” said Daae.
GLSDB is the development of a teaming agreement between Boeing and Saab signed in August 2014. The solution integrates the Boeing GBU-39/B Small Diameter Bomb I with the legacy M26 rocket motor from the Multiple Launch Rocket System (MLRS), using an interstage adaptor. Weighing 600 lbs (272 kg) and measuring 154 in (391 cm) in length, 9.5 in (24 cm in diameter) and with a deployed wingspan of 63.3 in (160.8 cm), GLSDB has a range of forward range of more than 150 km and a backward range of 70 km.
The weapon system is furnished with a fragmentation multipurpose warhead, an integrated electronic safe/arm fuze (ESAF) system with programmable impact and delay settings, and a height of burst sensor. Terminal accuracy is delivered by Global Positioning System (GPS)-supported Inertial Navigation System (INS) guidance – which is initiated after the motor is disconnected and the wings unfold – aided by an Anti-jam and Selective Availability Anti-Spoofing Module (SAASM) and an Advanced Core Processor Two (ACP 2) Module.
The GLSDB solution is able to leverage variant developments for the baseline GBU39/B SDB I, including Laser GLSDB, which is a semi-active laser (SAL)-guided option for engaging moving targets.
While currently optimised as a land-based surface-to-surface application, Daae said that the GLSDB concept is also gaining traction in the maritime domain, in coastal defence and ship-borne applications.
“The SAL variant is a version of the current air-launched SDB I. But we tested it in ground-launched mode during the trials at Eglin in 2017, and the SAL seeker performed fine. So, a SAL version could be used for slower moving targets such as larger warships, and we could send up to 12 at one target. There are also some nations looking to use GLSDM from smaller vessels, and because all the guidance is within the effector, all we’d need is a launcher, and to know our own position. But it could also be launched from a container on board a ship,” he added.
Other GBU-39/B developments that could be leveraged for GLSDB include Focused Lethality Munition (FLM) – an option for low collateral damage and, in the future, home on radar/jammer, area attack and advanced seeker options.
Would love to see how the economics on this fair when one negates the fact that it is utilizing surplus rocket motors (for which only a few thousand may exist that can be recapitalized) but this looks very promising though US Army wants that much or more range from its MLR solution with a faster time to target. This is great for Ground forces like Sweden and Norway and many others who may not have larger fires at their disposal and can use the SDB as a means to provide effects beyond your standard MLRS.